Windows + Doors: Retrofit

Why it Matters. How we do it.

Often seen as a cosmetic upgrade, poorly performing glazing and badly installed doors are weak points in the building envelope. They allow heat to escape, cold to creep in, and energy bills to rise. That's not just inefficient.. it's avoidable.

We treat windows and doors as part of the overall strategy: not in isolation, but as essential components in achieving real, measurable outcomes in energy performance, comfort, and carbon reduction.

Why Windows and Doors Matter in Retrofit

Most existing homes were built before energy performance was a consideration.

Draughts, single glazing, and poorly sealed frames are common. Left unaddressed, these areas can account for over 25% of heat loss in a home.

In a low-carbon retrofit, everything is connected. You can install all the insulation you like, but if your windows leak air or your doors let in the cold, the system fails.

What We Focus On

1. Performance, Not Appearances

We specify based on U-values, air permeability, and frame construction, not brochure images. Most of our retrofit projects use triple-glazed units with airtight timber or timber-aluminium composite frames, all installed to high airtightness standards.

Every product is chosen for a reason, backed by data.

2. Installation is Critical

A high-performance window installed poorly is a liability. We only use trained teams who understand building physics, thermal bridging, and airtightness detailing.

We ensure airtight membranes, sealing tapes, and expansion foams are applied correctly - because detail matters.

3. The Right Material for the Right Job

We lean toward FSC-certified timber and low-carbon materials where practical. Every product must meet our thresholds for durability, sustainability, and performance. We avoid uPVC wherever possible due to its lifecycle impact.

4. Understanding Context

We work with what's already there. In retrofit, that often means navigating awkward reveals, limited openings, or heritage restrictions. Where necessary, we integrate secondary glazing, vacuum units, or bespoke solutions to balance performance with planning constraints.

5. A System, Not a Surface Fix

Windows and doors don't sit in isolation. We look at:

• Solar orientation - for passive gains

• Thermal bridging at reveals and sills

• Ventilation strategy - to prevent condensation and maintain indoor air quality

• Airtightness testing - to verify performance Everything is part of the wider fabric strategy.

What to Expect from Stoic Homes

We approach every project with the same mindset:

Do what works. Leave out what doesn't. Build for the long term.

That means no trends, no guesswork, and no greenwash. Just results. If you're serious about reducing your home's energy use, improving comfort, and making long-term improvements with integrity - we're ready to help.